Abstract
The preliminary phytochemical screening of extracts of Rumex vesicarius L. and Ziziphus spina-christi (L.) Willd. showed the presence of compounds that are biologically active against the two root rot pathogens Drechslera biseptata and Fusarium solani in vitro. The relative efficacy of this action, however, differed according to the extracted plant, solvent used, extract concentration, the target fungus and phase of growth. Ethanolic extract ranked first, followed by the remaining aqueous layer fraction. Eight flavonoid subfractions (rutin, quercetin, myricetin, apigenin, quercetin-3-O-galactoside, luteolin, kaempherol and kaempherol-3-O-robinoside) and six flavonoid subfractions (apigenin-7-O-glucoide, quercitrin, quercetin, isovitexin, rutin and quercetin-3-O lucoside-7-O-rhamnoside) were isolated from the remaining aqueous layer fraction of R. vesicarius and Z. spina-christi, respectively. Generally, spore production and germination as well as cellulolytic and pectolytic activity of F. solani were affected by plant extracts more than that of D. biseptata. F. solani failed completely to produce spores when treated with ethanolic extract of Z. spina-christi at the concentration of 20%. However, growth of D. biseptata was more sensitive to plant extracts than that of F. solani. Maximum activity of plant extracts was observed against spore production. It was evident that plant extracts could provide potential source of antifungal compounds.